1. Field of the Invention
The present invention relates to a capsule medication administration system which is ingested into a living body and which performs medication for a diseased part such as a superficial disorder of the digestive organs or the like, and to a capsule medication administration method.
The present invention claims the priority of Japanese Patent Application 2003-343199 which was filed on 1 Oct. 2003, and incorporates its contents herein.
2. Description of Related Art
Nowadays, as means for administering a drug to a patient more safely and also more effectively, attention is being directed towards drug delivery systems (DDS: Drug Delivery System). Such a drug delivery system is a system which uses a drug more effectively by regulating the biological activity of the medicament and its side effects, targeting the diseased part, controlling the release of the drug (controlled release), improving the absorption of the drug, regulating the chemical stability and the metabolic activity and so on of the drug, and causing the drug to act upon a superficial disorder within the living body in the required amount and for just the required period of time. With such a drug delivery system, the technique for taking advantage of it is different according to the type of the disorder; for example, if the superficial disorder which is a diseased part is a malignant tumor, a technique is obtained of targeting and controlled release and the like.
On the other hand, as a device for checking upon the state of health of a patient easily, there is a known capsule type medical device which is orally ingested to within the living body. With this kind of capsule type medical device, various types of information may be provided; for example, it is known to take photographs at random of various parts within the living body, to take samples or the like from within the living body, to release a drug, and the like. As one such device, there is known a capsule endoscope which can form an image after releasing a foaming agent at a predetermined position (the large intestine) within the living body and distending the luminar portion within his body (for example, refer to paragraph 0006 through paragraph 0049 and to FIG. 1 through FIG. 5 of Japanese Unexamined Patent Application, First Publication No. 2003-38424).
The above described capsule endoscope is provided with a capsule shaped body which has a hemispherical shaped transparent member at its one end surface and a hemispherical mesh member at its other end surface. Within the transparent member there are provided a LED which emits light for illumination to the interior of the living body, and an image formation optical system which forms an image of the interior of the living body. Furthermore, a pH sensor is provided to the capsule body so as to be exposed at its outer surface. The pH value which has been detected by this pH sensor is sent to a control processing circuit, and, when it has been decided from the change of the pH value that the capsule has arrived at the large intestine, this is transmitted from a transmission antenna towards the outside of the living body. Furthermore, as well, the image data which has been formed into an image by the above described image formation optical system is transmitted from the transmission antenna towards the outside of the living body, after having been subjected to predetermined processing. Moreover, a plurality of micro capsules are housed on the inside of the mesh member, and are broken down by emission of ultrasound, and a foaming agent is stored in the insides of these micro capsules which generates a gas by reaction with water.
When a check is to be performed by using this capsule endoscope, the patient first swallows the capsule endoscope so as to ingest it to within his body. The capsule endoscope which has been ingested to within the living body moves within his digestive organs while detecting the pH value within his body by using the pH sensor. When the capsule endoscope arrives at the large intestine, the control processing circuit decides, based upon change of the pH value which has been detected by the pH sensor, that the capsule endoscope has arrived at the large intestine, and issues a notification to that effect to the exterior of the living body from the transmission antenna. When this signal which has been transmitted is received by a receiver or the like on the outside of the living body, the medical staff emit an ultrasonic wave towards the living body using an ultrasonic wave generator. When the ultrasonic wave is emitted, it breaks down the micro capsules, and the foaming agent inside them is released within the large intestine through the mesh member. The foaming agent which has been released within the large intestine reacts with the water component within the large intestine and generates gas, thus distending the large intestine. By the large intestine being distended, it becomes possible to form an image using the image formation optical system over a wide range of the interior of the large intestine which has thus been distended.
In this manner, the above described capsule endoscope is one with is equipped with the function of releasing the foaming agent from the micro capsules at a predetermined position (the large intestine) in the living body, as described above, i.e. with the functions of targeting and controlled release. In particular, new attention is being paid to this kind of capsule type medical device as one means for implementing the above described drug delivery system, since it can simply and conveniently be ingested to the interior of the living body.